Effectiveness of BNT162b2 against COVID-19 in adolescents

Powell, Annabel A; Kirsebom, Freja; Stowe, Julia; McOwat, Kelsey; Saliba, Vanessa; Ramsay, Mary; Bernal, Jamie Lopez; Andrews, Nick; Ladhani, Shamez

doi:10.1016/s1473-3099(22)00177-3

Cited by 60 publications

(72 citation statements)

References 7 publications

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“…Notwithstanding these limitations, consistent findings were reached, indicating rapid waning of vaccine protection against symptomatic Omicron infection that are consistent with findings of other studies for effectiveness against Omicron infection (with no BA.1/BA.2 subvariant specified) 42 – 48 . Moreover, with the mass scale of PCR testing in Qatar 13 , the likelihood of bias is perhaps minimized.…”

Section: Discussionsupporting

confidence: 87%

Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar

et al. 2022

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SARS-CoV-2 Omicron BA.1 and BA.2 subvariants are genetically divergent. We conducted a matched, test-negative, case-control study to estimate duration of protection of the second and third/booster doses of mRNA COVID-19 vaccines against BA.1 and BA.2 infections in Qatar. BNT162b2 effectiveness was highest at 46.6% (95% CI: 33.4–57.2%) against symptomatic BA.1 and at 51.7% (95% CI: 43.2–58.9%) against symptomatic BA.2 infections in the first three months after the second dose, but declined to ~10% or below thereafter. Effectiveness rebounded to 59.9% (95% CI: 51.2–67.0%) and 43.7% (95% CI: 36.5–50.0%), respectively, in the first month after the booster dose, before declining again. Effectiveness against COVID-19 hospitalization and death was 70–80% after the second dose and >90% after the booster dose. mRNA-1273 vaccine protection showed similar patterns. mRNA vaccines provide comparable, moderate, and short-lived protection against symptomatic BA.1 and BA.2 Omicron infections, but strong and durable protection against COVID-19 hospitalization and death.

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Section: Discussionsupporting

confidence: 87%

Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar

et al. 2022

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“…The declining VE against infection is similar to results from England, where VE against Omicron and Delta in adolescents aged 16-17 years decreased from 76% and 93% after 7-13 days to 23% and 84% ≥70 days post second dose, respectively. 3 In the US, 2-dose VE against Omicron hospitalization for those aged 12-15 and 16-17 years was 92% and 94% after 14-149 days compared to 73% and 88% after ≥150 days, respectively. 4 This difference in VE over time since second dose was not statistically significant, whereas declines in VE against emergency department (ED) visits were.…”

Section: Discussionmentioning

confidence: 95%

Vaccine effectiveness of BNT162b2 against Omicron and Delta outcomes in adolescents

Buchan

Nguyen

Wilson

et al. 2022

Preprint

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Introduction Data on vaccine effectiveness (VE) against Omicron in adolescents are limited. We estimated 2-dose and 3-dose VE against Omicron and Delta in adolescents aged 12-17 years in Ontario, Canada. Methods We conducted a test-negative design study among SARS-CoV-2-tested adolescents aged 12-17 years between November 22, 2021 (date of first Omicron detection) and March 6, 2022; we assessed Delta outcomes prior to January 2, 2022. We used multivariable logistic regression to compare the odds of vaccination in cases to symptomatic test-negative controls and calculated VE as 1-adjusted odds ratio. Results VE was lower against symptomatic Omicron infection than against Delta and decreased more rapidly over time, from 51% (95%CI, 38-61%) in the 7-59 days following a second dose to 29% (95%CI, 17-38%) after 180 days, compared to 97% (95%CI, 94-99%) and 90% (95%CI, 79-95%) for the same intervals against symptomatic Delta infection. Overall, 2-dose VE against severe outcomes caused by Omicron was 85% (95%CI, 74-91%) ≥7 days following a second dose and estimates were similar over time. VE against symptomatic Omicron infection was 62% (95%CI, 49-72%) ≥7 days following a third dose. Discussion Two-dose VE against symptomatic Omicron infection wanes over time in adolescents. While lower than observed against Delta, protection against severe outcomes appears to be maintained over time. A third dose substantially improves protection against Omicron infection, but 3-dose VE is only moderate at approximately 60% in the early period following vaccination and the duration of this protection is unknown.

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“…Although increased protection against infection was observed with early variants of SARS-CoV-2, BNT162b2 has been found to offer limited, short-term protection against the omicron variant. 6,7 In May, 2022, the US Centers for Disease Control and Prevention recommended a third dose of BNT162b2 for children aged 5-11 years, 8 but real-world experience in adults indicates that protection against SARS-CoV-2 infection will also wane within a few weeks after the third dose. 7 Therefore, unless the plan is to revaccinate every few months, vaccination alone is unlikely to be an effective strategy for preventing SARS-CoV-2 infections.…”

Section: Covid-19 Vaccination For Children Aged 5-11 Yearsmentioning

confidence: 99%

“…11 Although Sacco and colleagues do not differentiate between those with and without comorbidities, BNT162b2 will probably also help protect healthy children against their very low risk of severe COVID-19, as it does in adolescents and adults. 6,7 However, this protection is lower in children aged 5-11 years than in older age groups, possibly because of their lower vaccine dose (10 mg vs 30 mg). 12 Another reason for vaccinating children aged 5-11 years, as has been shown in adolescents, 13 would be to protect against multisystem inflammatory syndrome in children (MIS-C), which is a rare but serious post-infectious, hyperinflammatory syndrome that typically occurs 2-6 weeks after SARS-CoV-2 infection.…”

Section: Covid-19 Vaccination For Children Aged 5-11 Yearsmentioning

confidence: 99%